This invention relates to grain storage tanks on agricultural harvesting machines such as combines. More particularly, the invention relates to covers for such grain storage tanks. Such cover is used to close off a top opening of the grain storage tank, thus to shield grain, carried in the tank, from adverse weather conditions. Such cover is also used to protect the tank from e.g. tree branches which might otherwise drop into the tank through the top opening in the tank.
It is common for a conventional combine or other harvester to include a large capacity grain storage tank of e.g. about 100 bushels or more, for receiving and temporarily storing the grain or other harvested crop until such time as the harvested crop material can be unloaded from the harvester into an e.g. truck, wagon, or other vehicle which is used to carry the crop away from the field where the crop was grown, such as for permanent storage on the farm, or to an off-farm purchaser.
Hereinafter, the harvested crop will be referred to as grain. It will be understood that other crop materials can be harvested using such machines, and that all such other crop materials are thus intended to be included in such recitation of grain.
Also hereinafter, the harvester will be referred to as a combine, it being understood that the invention applies to other harvesting machines which include thereon tanks for temporary storage of the harvested crop.
Typically, such grain-receiving tank on the combine includes a plurality of underlying walls which define the tank as a receptacle. The underlying walls define a top opening of the tank. The top opening provides ready access to the interior of the tank from the top of the tank. The top opening also provides a visual inspection access for inspecting the condition and quality of the grain being carried in the tank. Further, the top opening enables the operator of the combine to have a top view of the upper portion of the tank from the operator""s station in the cab, thus to see the grain in the tank as the grain begins to extend above the top opening in a nearly full tank, whereby the operator can ensure emptying the tank before the tank is over-filled. Further, the top opening provides an exit path for exhaust from the tank of dust which can be carried into the tank with the harvested grain.
It is common practice to equip the grain storage tank with one or more cover members, thus to overlie and close the top opening of the tank when desired, for example to keep out rain, dirt, and other foreign material. Such cover members, in the open orientation, provide access to the top opening of the underlying tank. Cover members also can serve, in the closed orientation, to close off the top opening of the tank, thus to prevent access to the tank through the top opening. Such closure can be particularly desirable during road transport for reducing the overall height of the combine. Such closure further inhibits entrance of dirt, dust, and other detritus into the tank. Such closure may also be desirable during certain harvesting operations for shielding the grain in the tank from rain.
Where possible, and commonly, grain tank covers on combines are retained in an open condition during the harvesting process, enabling an unobstructed top view of the harvested and stored grain, and potentially providing an increase in capacity of the tank by virtue of allowing a central portion of the pile of grain to extend somewhat above the top of the underlying grain tank.
A wide variety of grain storage tank covers are employed in conventional practice. For example, from 2 to 4 metal cover panels can be used to cover the top opening of the tank. Metal covers have the advantage of being strong and sturdy, but have the disadvantage of being bulky, heavy to install, heavy to transport as part of the combine, heavy to lift for opening the cover to thereby expose the top opening of the tank for the above-noted access and use, and such covers can require frequent alignment. To facilitate opening of such heavy covers, gas springs or other resilient apparatus are commonly used to assist in raising the cover panels and thus in opening the tank cover.
Other conventional embodiments of tank covers use flexible sheet material such as canvas or flexible plastic, stretched over a metal or other skeletal framework. Such structures are less heavy, and therefore less cumbersome. However, the flexibility of such cover materials renders the dimensions quite flexible, changeable when erected to thus expose the top opening of the grain storage tank, and potentially enables spillage of contents of the tank where the dimensions of the cover shift during use. In addition, the flexibility of such materials further prevents facile attachment of opening and closing apparatus, whereby facile opening and closing of such covers to enable access to the underlying tank is not enabled.
In addition, tank cover panels which extend upwardly from the outer edge of the tank top opening are somewhat susceptible to wind and other forces having horizontal components. Thus, tank cover panels which extend upwardly from the outer edge of the tank top opening, when in the open position, need to be firmly secured to the walls or other structure of the underlying tank in order to prevent such covers from being adversely affected by the wind. Even where firmly secured, the flexible nature of such flexible sheet materials precludes facile opening and closing of such structures, thus to control access to the tank from above.
It is known to provide permanently-positioned tank cover panels which extend inwardly from the edges of the tank opening, and to have pivoting metal cover panels which pivot upwardly from the permanently-positioned cover panels, whereby an inner portion of the area of the top opening of the grain storage tank can thus be opened to ambient. The advantage of such limited size opening is that the cover panels are sufficiently small as to have sufficiently low mass that simple, light-weight apparatus can be used in lifting of such panels, whereby lifting such panels to open a portion of the top opening for access to the tank is facilitated. However, such limited size opening limits the benefits which attend additional volume capacity of the tank.
It is also known to provide a semi-cylindrical plastic tank cover which entirely closes off the top opening of the tank when the cover is installed. Such plastic cover has a small off-center access panel which slides from an edge of the cover upwardly along the arcuate outline of the cover, thus to provide limited access to the interior of the tank adjacent an edge of the tank. Such semi-cylindrical tank cover thus makes little provision for increasing capacity of the tank at the edge of the tank, whereby only limited capacity increase is available, and is generally by piling the grain in the center of the tank, above the top edge of the tank, and accommodating any cascade of the pile toward the edge of the tank, up to the top edge of the underlying tank. Such conventional tank cover thus makes little provision for increasing capacity of the tank.
In the above noted conventional tank covers, in those covers which provide increased height of the tank, thereby to increase tank capacity, the cover panels are separate and distinct from each other; and any spaces between the respective covers constitute potential for spillage of the grain when the grain in the tank reaches above the top edge of the underlying tank. Some of such tank covers provide rigid filler panels which bridge and fill the spaces between the respective primary and/or secondary panels. However, such rigid filler panels are expensive to build, are mechanically complex, and constitute substantial extra weight.
Another method of dealing with spacing between adjacent cover panels is to structure the tank cover such that spacing tolerances between surfaces and/or edges of adjacent tank cover panels are carefully controlled. Such careful control in manufacture of the panels, as well as in the assembly of the panels, is costly, is subject to failure, and can require frequent adjustment.
It would thus be desirable to provide a tank cover which is rigid, durable, and strong, which is sufficiently light in weight such that the entire tank cover can be raised by a single simple underlying mechanical linkage energized by a low power lift mechanism, and which has low cost, easily maintained closures at the corners of the tank cover so as to limit spillage of grain at the tank corners.
It is a further objective to provide a such tank cover which adds substantially to the carrying capacity of the combination of tank plus cover when the cover is open and fully erect.
It is yet another object to provide a such tank cover wherein the underlying mechanical linkage is also configured to, simultaneously with lifting of the cover panels to thereby open the tank cover, lift the clean grain elevator, to an elevation above the top edge of the underlying tank, whereby grain can be expelled into such tank-plus-cover combination by the elevator at an elevation well above the top edge of the underlying tank, and whereby the capacity of such tank-plus-cover combination can be increased up to the top edges of the vertically-extending cover panels.
This invention provides novel covers for grain storage tanks on harvesting machines such as combines. Rigid cover panels of the cover are preferably fabricated, as a double-wall structure, of generally rigid polymeric sheet materials so as to limit weight of the cover while providing desired levels of strength and rigidity. The rigid cover panels can be pivoted about the top edges of an underlying grain storage tank whereby the cover panels are transformed into a height extension of the underlying grain storage tank, thus to increase the grain-carrying capacity of the underlying tank. Flexible transition panels are preferably mounted to the rigid cover panels so as to bridge spaces between the rigid cover panels when the rigid cover panels are raised to their upright, tank-extending orientations. A preferably single underlying actuator in the tank, in combination with mechanical linkages, simultaneously raises all the rigid cover panels, all the flexible transition panels, and the discharge end of the clean grain elevator which discharges grain into the tank.
In a first family of embodiments, the invention comprehends a grain storage tank cover for use in combination with an underlying grain storage tank on an agricultural harvesting machine. Such grain storage tank has a plurality of walls defining an underlying tank structure, and a top opening to be overlain and closed by the grain storage tank cover. The grain storage tank cover comprises a plurality of rigid polymeric cover panels each having a proximal edge, an opposing distal edge, and side edges. The polymeric cover panels are adapted for pivoting attachment to such underlying grain storage tank at the proximal edge such that each cover panel, when attached to such grain storage tank, is adapted to pivot at such proximal edge and thereby to pivot between a closed position covering at least a portion of the top opening, and an open position facilitating access to such grain storage tank from above. The plurality of rigid polymeric cover panels are adapted collectively to close a such top opening of the underlying tank when pivoted downwardly, and to expose such top opening of the underlying tank when pivoted upwardly.
The tank cover preferably comprises a single lifting and lowering actuator underlying and connected to the cover panels by a single mechanical linkage assembly, for pushing the cover panels upwardly, and for lowering such cover panels, in pivoting motions about edges of the top opening of the underlying tank.
The tank cover preferably includes flexible fabric transition panels, each mounted to respective adjacent ones of the rigid cover panels proximate the side edges of the rigid cover panels, so as to bridge, and thereby close, any open space between the side edges of the respective adjacent cover panels when the tank cover is open, and to fall by gravity into the underlying grain storage tank when the rigid tank cover panels are moved to a closed position.
In some embodiments, the plurality of tank cover panels comprise first and second opposing primary cover panels, and third and fourth opposing support cover panels, oriented, in the open configuration, generally perpendicular to the first and second primary cover panels and adapted for pivoting attachment to an underlying grain storage tank at proximal edges of the cover panels. When attached to such underlying grain storage tank, each such third and fourth polymeric cover panel is adapted to pivot at the proximal edge of the respective cover panel and thereby to pivot between a closed position covering at least a portion of the top opening, and an open position facilitating access to such grain storage tank from above. Each of the flexible fabric transition panels is secured to, and serves as a closure between, one of the primary cover panels and one of the support cover panels.
In preferred embodiments, the compositions of the polymeric cover panels comprise acrylonitrile butadiene styrene copolymer.
In preferred embodiments, the rigid polymeric cover panels comprise double wall construction defining crossing networks of intersecting ribs on corresponding walls of a given cover panel.
Also in preferred embodiments, the flexible fabric panels comprise composite sheet material. The composite sheet material comprises a fibrous substrate, and an abrasion resistant polymeric coating on the fibrous substrate. The flexible fabric panels having sufficient mass, and are so attached to the cover panels, that when the cover panels are lowered to thereby close the top opening, central portions of the transition panels are pulled by gravity so as to move downwardly into the underlying grain storage tank and away from the rigid cover panels.
In preferred embodiments, the mechanical linkage assembly comprises underlying mechanical linkages connecting the single actuator to each of the rigid polymeric cover panels. The single actuator, when mounted to such underlying grain storage tank and in combination with the mechanical linkages, being effective, upon actuation of the actuator, to cooperatively lift or lower all of the polymeric cover panels, thereby to open or close the grain storage tank cover over the tank.
In preferred embodiments, the mechanical linkages include elevator mounting structure for mounting the clean grain elevator to the mechanical linkages such that, when the actuator is activated to open or close the cover panels, an elevator mounted to the elevator mounting structure is cooperatively raised or lowered in such underlying grain storage tank, preferably while the cover panels are correspondingly being raised or lowered.
In preferred embodiments of the tank cover, first and second ones of the rigid polymeric cover panels, when the cover is closed, form a joint therebetween at respective distal edge regions of the respective cover panels, and cooperatively define a rain gutter therebetween effective to direct rain water toward side edges of the first and second rigid polymer cover panels.
In a second family of embodiments, the invention comprehends a grain storage tank cover, for use in combination with an underlying grain storage tank on an agricultural harvesting machine. The underlying tank has a plurality of walls defining an underlying tank structure, and a top opening to be overlain and closed by the grain storage tank cover. The grain storage tank cover comprises at least a first pair of opposing generally rigid polymeric cover panels, adapted for pivoting attachment to such underlying grain storage tank. When attached to such grain storage tank, each such pair of rigid polymeric cover panels is movable between a closed position covering at least a portion of the top opening, and an open position facilitating access to such grain storage tank from above. The tank cover further comprises actuator apparatus comprising a single lifting and lowering actuator underlying, and connected to, the rigid polymeric cover panels, and mechanical linkages underlying the cover panels and connecting the single actuator to each of the polymeric cover panels. The single actuator, when mounted to such underlying grain storage tank and in combination with the mechanical linkages, is effective, upon actuation of the actuator, to cooperatively and preferably simultaneously lift all of the rigid polymeric cover panels, thereby to open the grain storage tank cover.
In preferred embodiments, the single lifting and lowering actuator extends upwardly along an arcing path, and pushes the cover panels upwardly in pivoting motions about edges of such top opening.
In a third family of embodiments, the invention comprehends a grain storage tank cover, for use in combination with an underlying grain storage tank on an agricultural harvesting machine. Such grain storage tank has a plurality of walls defining an underlying tank structure, and a top opening to be overlain and closed by the grain storage tank cover. The grain storage tank cover comprises at least first and second opposing generally rigid cover panels, which may or may not be plastic, and may in this family of embodiments be metal. Each such rigid cover panel has a proximal edge, an opposing distal edge, and side edges. The cover panels are adapted for pivoting attachment to such underlying grain storage tank at the proximal edges and, when so attached to such grain storage tank for pivoting about the proximal edges, each such rigid cover panel is movable between a closed position covering at least a portion of the top opening, and an open position facilitating access to such grain storage tank from above. The cover further comprises flexible fabric transition panels, each mounted to respective adjacent ones of the generally rigid cover panels proximate the side edges of the cover panels, so as to bridge, and thereby close, any open spaces between respective adjacent ones of the side edges of the respective adjacent cover panels when the tank cover is open, and wherein central portions of the transition panels fall by gravity into such grain storage tank when the tank cover is closed.
In some embodiments, the first and second generally rigid cover panels comprise primary cover panels. The tank cover further comprises third and fourth opposing generally rigid support cover panels, oriented generally perpendicular to the first and second cover panels when in the open configuration, and adapted for pivoting attachment to such underlying grain storage tank. When attached to such underlying grain storage tank, each such third and fourth cover panel is movable between a closed position covering at least a portion of the top opening, and an open position facilitating access to the grain storage tank from above. Each of the flexible fabric transition panels is secured to, and serves as a closure between, one of the primary panels and one of the support panels.